24 October 2012. The Open Geospatial Consortium (OGC®) seeks
public comment on the candidate "GML-NIL profile" of the OGC Geography
Markup Language (GML) Encoding standard. GML is a widely used XML grammar for encoding
information about geographical features. The GML-NIL profile provides a way to allow
data providers to make a best effort to supply data according to an application
schema, even if they do not have values for all feature properties. This is
achieved by marking the application schema as a whole as ‘nillable=true’ and
using OGC ‘nil’ URIs in links for missing data. This reverses the usual pattern
which has a default value of nillable=false.

The GML-NIL pattern of use has been used informally for
several years in Earth and environmental science applications, and this candidate
standard merely aims to formalize and document the practice. It is expected to
be useful in many applications where a heterogeneous community wishes to enable
participation by a wide variety of members with different capabilities and data
sources. The submission team is composed of members of the GeoSciML project.

The OGC is an international consortium of more than 465
companies, government agencies, research organizations, and universities
participating in a consensus process to develop publicly available geospatial
standards. OGC Standards support interoperable solutions that
"geo-enable" the Web, wireless and location-based services, and
mainstream IT. OGC Standards empower technology developers to make geospatial
information and services accessible and useful with any application that needs
to be geospatially enabled. Visit the OGC website at http://www.opengeospatial.org/contact.